Even-odd chain dependent spin valve effect on a zigzag biphenylene nanoribbon junction

Abstract

The even-odd chain dependent spin valve effect was forecasted in some honeycomb graphene-like materials with zigzag edges. In this study, we confirm that the even-odd chain related spin valve phenomena also exist in a zigzag biphenylene nanoribbon (ZBN) junction. By modeling the ZBN junction with different even and odd chains subjected to a local Rashba spin orbit coupling(SOC) and a homogeneous magnetic field, we calculate the spin dependent conductance spectra between the source and the drain electrodes and find that the spin up(down) electron can be inhibited(allowed) to flow through the even(odd)-chain ZBN junction, which can be explained by the combined effect between the pseudo-parity conservation and magnetic field-tunable energy gap in the energy band theory. The switch on and off states of spin valve can be modulated by the most system parameters such as the Fermi energy, magnetic flux, and Rashba SOC. Furthermore, the ZBN can act as a gate-tunable spin generator and spin filter, in which we can get 100% polarized spin up(down) electrons with (no) spin-flipping from the even-chain ZBN junction, and only produce 27% polarized spin-converting electrons from the odd-chain ZBN junction. Our findings might be useful in designing future multi-parameter controllable spin valves by using the new carbon allotropes.

Magnetic transitions of biphenylene network layers induced by external perturbations

“…The experimental realization of BPN layers has sparked significant interests in exploring their electronic, phononic, mechanical, chemical, and thermal properties. 3–38 Recent studies 3,4 have revealed that the 2D BPN lattice exhibits intriguing electronic band structures such as type-II Dirac cones, 39 nearly flat bands, and saddle-point van Hove singularities (vHS). These characteristics are closely related to topological and correlation physics.…”

Engineering Two-Dimensional Nodal Semimetals in Functionalized Biphenylene by Fluorine Adatoms

“…Recently, another type of two-dimensional carbon allotrope, called the biphenylene network (BPN), was synthesized and has attracted significant interests in various properties of BPN layers including electronic, optical, mechanical, thermal, magnetic, and chemical properties. − Moreover, from the first-principles analysis, BPN turned out to exhibit another intriguing band dispersion called type-II Dirac fermion consisting of two heavily inclined cones, so that we have open Fermi surfaces instead of Fermi points or circles. , In type-II Dirac semimetals, one can have electron- and hole-type carriers simultaneously in contrast to the type-I case such as graphene. This intricate band shape may lead to a variety of unusual electronic phenomena such as anisotropic transport and magnetoresistance behavior − and undamped gapless plasmon modes .…”